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Abstract

Background

The structure of whole grain cereals is maintained to varying degrees during processing
and preparation of foods. Food structure can influence metabolism, including perceived
hunger and satiety. A diet that enhances satiety per calorie may help to prevent excessive
calorie intake. The objective of this work was to compare subjective appetite ratings
after consumption of intact and milled rye kernels.

Methods

Two studies were performed using a randomized, cross-over design. Ratings for appetite
(hunger, satiety and desire to eat) were registered during an 8-h period after consumption
of whole and milled rye kernels prepared as breads (study 1, n = 24) and porridges
(study 2, n = 20). Sifted wheat bread was used as reference in both study parts and
the products were eaten in iso-caloric portions with standardized additional breakfast
foods. Breads and porridges were analyzed to determine whether structure (whole vs.
milled kernels) effected dietary fibre content and composition after preparation of
the products. Statistical evaluation of the appetite ratings after intake of the different
breakfasts was done by paired t-tests for morning and afternoon ratings separately,
with subjects as random effect and type of breakfast and time points as fixed effects.

Results

All rye breakfasts resulted in higher satiety ratings in the morning and afternoon
compared with the iso-caloric reference breakfast with sifted wheat bread. Rye bread
with milled or whole kernels affected appetite equally, so no effect of structure
was observed. In contrast, after consumption of the rye kernel breakfast, satiety
was increased and hunger suppressed in the afternoon compared with the milled rye
kernel porridge breakfast. This effect could be related to structural differences
alone, because the products were equal in nutritional content including dietary fibre
content and composition.

Conclusions

The study demonstrates that small changes in diet composition such as cereal grain
structure have the potential to effect feelings of hunger and satiety.

Trial registration

Background

A high intake of dietary fibre and whole grain foods is associated with a lowered
risk of body weight gain, partly owing to an increased feeling of satiety preventing
excess energy intake [1,2]. Satiety, or the feeling of fullness, is primarily a result of neural and hormonal
signalling throughout the gastrointestinal tract with the purpose of regulating further
intake and optimizing digestion and absorption [3]. The influence on perceived satiety varies according to several chemical and physical
properties of foods. Food structure changed by milling of cereal grains is one attribute
that influences the metabolic response [4]. The botanical structure of cereal grains such as wheat, oats, and rye is maintained
to varying degrees during food processing. The grains can be cracked, cut, rolled
or milled before being used in a wide range of whole grain products including breads,
pasta and breakfast cereals. Rye is a cereal traditionally consumed as whole grain
in the Eastern and Nordic Countries. Whole grain rye contains about 20 g dietary fibre
per 100 g, which is higher than in other commonly consumed grains [5].

A few studies have investigated the impact of cereal grain structure on satiety. Two
studies on whole grain wheat showed that breads including whole kernels increased
satiety more than breads made with whole grain flour, at 15 min after intake [6] and during 90 min after intake [7]. When whole kernels, cracked kernels, coarse and fine wheat flour were prepared as
oven-baked products, no significant difference on satiety was seen over a time period
of 2 h [8]. Also, no variation on postprandial satiety measured for 3 h was found in a comparison
of whole and milled barley kernels prepared as porridges [9]. Both studies does however show that grain structure influence the metabolic response,
in that glucose and insulin levels were lower after intake of kernels than after flour.
Satiety is commonly measured in a period of 0.5-3 hours and longer-term effects are
rarely explored. An overnight effect was studied by serving breads made with cut or
whole barley kernels as evening meals [10]. The satiating effect of the products did not differ when measured in the following
morning. We have previously shown an increased satiety lasting for up to 8 hours after
intake of rye porridge made from whole grain rye flakes, compared to sifted wheat
bread [11]. In an additional study [12], rye bread made from finely ground flour, resulted in an increased satiety during
the first 4 h after consumption. However, in this study there was no difference in
satiety in the afternoon. Together, this suggests a potential of cereal structure
(flakes vs. flour) to influence satiety up to 8 hours after intake.

The aim of the present study was to investigate if variation in rye grain structure
influences perceived appetite during 8 hours. Whole rye kernels and milled rye kernels
were compared in a two-part study. The first part compared breads made with milled
and whole rye kernels, and the second part porridges of milled and whole rye kernels.
Both study parts included a reference breakfast with sifted wheat bread. Special efforts
were taken to analyze potential differences in dietary fibre content and composition
between the products made from whole or milled rye kernels.

Methods

Subjects

Subjects were recruited by sending an inquiry via e-mail to students and employees
at the Swedish University of Agricultural Sciences, Uppsala, Sweden. Volunteers were
further informed in person about the study procedures and screened to determine their
eligibility for inclusion. The criteria for inclusion were the following: man or woman
aged between 20 and 60 years; body mass index (BMI) 18-27 kg/m2; habit of consuming breakfast, lunch and dinner every day; and willingness to comply
with the study procedures. Exclusion criteria were the following: intake of medicine
likely to affect appetite or food intake; any medical condition involving the gastrointestinal
tract; eating disorder; smoking; consumption of more than three cups of coffee per
day; change in body weight more than 10% during three months prior to screening; consumption
of any restricted diet such as vegan, gluten-free, slimming, etc.; pregnancy, lactation
or wish to become pregnant during the study period.

Weight and height were measured with the subjects wearing light indoor clothing but
no shoes and the data obtained were used to calculate BMI. Capillary blood samples
were taken in the fasting state for analysis of glucose, thyroid-stimulating hormone,
and haemoglobin and alanine aminotransferase.

Initial recruitment started in October 2008 for the bread study, which was performed
over 5 weeks starting in early November 2008. All subjects participating in the bread
study were invited to the porridge study, which was performed over 5 weeks starting
in early April 2009. Written informed consent was obtained from each subject. The
study was carried out in compliance with the Helsinki Declaration and was approved
by the Ethics Committee at Uppsala University, Sweden.

Study design

A randomized, cross-over design was used, with three treatments in each of the two
study parts. The test sessions (08:00-16:00) were separated by between 5 and 15 days
during which the subjects were asked to follow their ordinary diet. The subjects were
not informed about the aim of the study or about the content of the test products.
On the day prior to each test day, subjects were instructed not to conduct any vigorous
physical activity or drink any alcoholic beverages. They were also instructed to eat
dinner before 20:00 and to keep the dinner meal similar before each test occasion.
They were instructed not to eat or drink anything but water after 20:00.

Upon arrival in the morning (08:00) on test days, each subject was served one of the
test breakfasts. During eating, they were seated in a dining area and allowed to make
conversation but not regarding anything relating to the study. The subjects were seated
at separate tables according to which breakfast they were served, so that those sitting
together were eating the same type of breakfast. At the beginning of each session,
subjects were asked to fill out questionnaires regarding food and beverage consumption
and exercise pattern from the previous evening. After finishing the breakfast meal,
the subjects received a lunch bag to be eaten at 12:00 and were free to return to
their normal daily activities, such as office work or studies. During the day, they
were not allowed to conduct any heavy physical activity, including brisk walking,
and restricted to stay within the campus area. They were not allowed to eat or drink
anything except foods included in the study diet and moderate amounts of water. A
compliance form was filled out by each subject during the day to ensure that instructions
were followed.

Subjective feelings of appetite were assessed every 30 min, starting just before breakfast
at 08:00 and continuing until 16:00. The data were collected using a specially designed
program [13] on a handheld computer, model Palm z22 (Palm Inc, Sunnyvale, USA). At each appetite
recording, an alarm went off to remind the subject. The following three questions
were presented in sequence: 'How hungry do you feel right now?', 'How full do you
feel right now?' and 'How strong is your desire to eat right now?', along with three
respective scales marked at opposite ends: Not at all hungry/Extremely hungry, Not
at all full/Extremely full, Not at all strong/Extremely strong. The computer mimics
the use of pen and paper as it is operated by tapping the screen with a rubber pen.
When entering the score, the subjects were prevented from referring to a previous
rating. Like the conventional 100 mm visual analogue scale [14], the computerized system translates the mark that the subject makes along the scale
to a number between 0 and 100.

At 16:00, the subjects returned to the dining area to hand in the palm computers and
compliance forms. They were asked about any complications during the day. In the porridge
study, the subjects wore pedometers to count steps taken between 08:00 and 16:00.

Rye and wheat material

For the bread study, rye kernels commercially used in breads were used (Lantmännen
Cerealia, Vejle, Denmark). These untreated kernels were slightly cracked by rolling
(2 mm) in order to decrease the time for water absorption and soften the consistency.
Rye kernels developed for use as a rice replacer (Lantmännen Cerealia, Järna, Sweden)
were used in the porridge study. These kernels were steamed before being lightly cracked
by rolling (1.8 mm) in order to decrease cooking time. Both types of rye kernels described
above were used whole and milled to fine whole grain flours using a laboratory mill
(model 3100, screen size 0.8 mm, Perten Instruments, Stockholm, Sweden). Commercial
sifted wheat flour of high quality (Bagerivetemjöl, Nordmills, Malmö, Sweden) was
used in all breads, including the wheat reference bread.

Breads

Three types of bread were made in a small-scale bakery; bread with whole rye kernels,
bread with milled rye kernels and wheat reference bread. To create breads with acceptable
palatability and soft texture, rye comprised 50% of the total amount of flour. A higher
content of rye resulted in compact, crumbly breads, with low ability to prove during
fermentation.

Soaked rye kernels were prepared by adding rye kernels (900 g) to a pot of boiling
water (1350 g) and left to soak under lid for 60 min. Soaked milled rye kernels were
prepared by adding boiling water (1350 g) to milled rye kernels (900 g) in a plastic
container. After mixing by hand, the blend was covered with plastic wrapping and left
to soak for 60 min.

Both of the rye breads were then baked according to the same procedure. The soaked
rye was mixed with sifted wheat flour (900 g), fresh baker's yeast (75 g), gluten
(150 g), rape seed oil (90 g), syrup (90 g) and salt (27 g) and kneaded for 7 min
using a mixer (Varimixer, Bjørn, Wodschow & Co, Brøndby, Denmark). The dough was left
to rest at room temperature (~22°C) for 10 min, then weighed and divided equally into
six loaves. The loaves were left to prove for 30 min at 34°C and then baked at 200°C
for 40 min.

The wheat reference bread was made by mixing sifted wheat flour (1800 g), water (1050
g, 25°C), fresh baker's yeast (75 g), gluten (150 g), rapeseed oil (90 g), syrup (90
g) and salt (27 g) for 7 min. The dough was left to rest at room temperature for 10
min and then weighed and divided equally into six loaves. The loaves were left to
prove at 34°C for 30 min and then baked at 200°C for 30 min. The wheat bread used
as reference in the porridge study was baked in the same way, except that gluten was
excluded.

After cooling for approximately 2 h, the ends of the loaves were removed. Test portions
were weighed, packed individually into plastic bags and stored frozen until the night
before each test breakfast.

Porridges

The porridge of whole rye kernels was prepared by adding rye kernels (66 g) and salt
(0.75 g) to boiling water (155 g) and simmering gently for 11 min. By then all water
was absorbed by the kernels.

The porridge of milled rye kernels was made by adding milled rye (66 g) kernels to
boiling water (350 g), removing the pot from the heat and whipping the contents for
4 min to a smooth porridge.

Meals

Food intake was standardized in terms of type, amount and timing during the 8-h test
period. The test breads were served with the following additional foods: 10 g margarine
(40% fat), 24 g cheese (28% fat), 200 g orange juice and one cup of tea or coffee.
In the porridge study, the following additional breakfast foods were used: 10 g margarine
(40% fat), 60 g lingon berry jam and 200 g milk (1.5% fat). The subjects were allowed
one cup of tea or coffee with up to two sachets of milk (20 g, 1.5% fat). Choice of
hot drink was individually standardized between test occasions. No sugar or sweetener
was allowed. The breakfast meals provided 2550 kJ in the bread study and 1850 kJ in
the porridge study. The standardized lunch used in both study parts consisted of a
ready-made vegetarian pasta dish of 400 g providing 2040 kJ, 21 g of protein, 64 g
of carbohydrates and 16 g of fat per dish (Pasta pomodoro e mozarella, Gooh!, Stockholm,
Sweden) and was served with 40 g of cherry tomatoes and 40 g of cucumber. The breakfast
and lunch meals had to be consumed entirely and within 30 min. At 14:00, the subjects
ate an apple and could choose to drink a cup of tea or coffee, the drink was then
kept identical on the following test days.

Chemical analysis

Breads and porridges were freeze-dried, homogenized in a cyclone sample mill (Retsch,
Haan, Germany) and stored at -20°C. In order to obtain representative samples of the
porridges, samples were collected every test week. All the samples were analyzed at
least in duplicate and results are reported on a dry matter basis. Dry matter was
determined by drying the samples at 105°C for 16 h according to the AACC method 44-15A
[15]. Extractable and unextractable dietary fibre was analyzed according to the Uppsala
method [16]. The β-glucan content was determined using the Megazyme (Bray, Ireland) K-BGLU kit
[17]. Fructan was quantified by a spectrophotometric method using the K-FRUC kit (Megazyme,
Bray, Ireland) [18]. As the samples might contain raffinose-type oligosaccharides, they were treated
with α-galactosidase. Arabinoxylan weight-average (Mw) and number-average (Mn) molecular weights were determined using high performance size exclusion chromatography
coupled with multiple angle laser light scattering and refractive index detector [5]. Arabinoxylan fractions with retention time 30-44 min were included in the results,
as their molecular weight could be calculated with precision. Calcofluor average molecular
weight of β-glucan (Mcf) was analyzed using size exclusion chromatography with fluorescence detection and
Calcofluor concentration 0.0025% [19]. Molecules with molecular weight less than 104 g/mol are not detected and were thus excluded from the results. Fructan molecular
weight distributions were determined by high performance anion exchange chromatography
coupled with amperometric detection [20]. The samples were extracted with 80% ethanol to solublize fructan and inactivate
enzymes. For all components analyzed, the deviation between two analytical repeats
was less than 5%.

Statistical analysis

Ratings for satiety, hunger, and desire to eat were analyzed using Minitab (version
15, LEAD technologies, inc, USA). The level of significance was set at p < 0.05. Missing
values (< 1%) were replaced by an average of the ratings for the same point in time
and treatment. ANOVA was performed as paired t-tests and Tukey comparisons using subjects
as random effect and type of breakfast and time points as fixed effects. Separate
analyses were performed for morning (08:30-12:00) and afternoon ratings (12:30-16:00).

Results

Subjects

Of the 27 subjects recruited initially, 24 complied with the study procedures and
completed the bread study. The three drop-outs were caused by illness (not related
to the study), energy requirements exceeding those given in the standardized study
diet and not meeting the health criteria. In the porridge study, 20 subjects of the
23 recruited initially met the criteria and completed the study. The three drop-outs
were caused by failure to comply with the study procedures. All subjects were within
a healthy range of measured health parameters (Table 1). Results from pedometer readings showed that the mean number of steps taken between
08:00 and 16:00 was not significantly different between the treatments.

Test products

Within each study part, test products were served in portions providing similar caloric,
protein, fat and available carbohydrate content (Table 2), together with standardized additional foods. The rye products contained more dietary
fibre and portion size was higher mainly due to higher water content.

Table 2. Weight, energy and nutrient content per portion of the test products as served

The breakfast and lunch meals were well liked and finished completely within 30 min.
No adverse events were recorded. Anecdotally, many commented on the large portion
size of the porridges, especially the milled kernel porridge.

The total dietary fibre content including fructan in the breads with whole rye kernels
(12%) and milled rye kernels (13%) differed only slightly (Table 3). Likewise, total dietary fibre content in the two porridges was similar: 21% and
22% in the whole and milled kernel porridge, respectively. The difference was probably
a result of formation of resistant starch (type III, retrograded amylose). Amounts
of the other dietary fibre components (arabinoxylan, arabinogalactan, β-glucan, fructan
and klason lignin) were similar for both rye breads and porridges, respectively.

Table 3. Dietary fibre content and composition in breads and porridges made from whole and
milled rye kernels, and two reference breads (% of dry matter)

Slight differences due to milling were observed, as the bread with whole kernels had
slightly higher Mw and Mn and lower polydispersity index for extractable arabinoxylan than the bread with milled
kernels (Table 4). The porridges were similar in molecular weight parameters of extractable arabinoxylan.
The molecular weight distribution pattern showed a higher proportion of low molecular
mass fraction of extractable arabinoxylan in the bread made from milled rye kernels
(Figure 1). Extractable arabinoxylan distribution pattern in the porridges was similar and
fell within a narrow range.

Table 4. Weight (Mw) and number (Mn) average molecular weight and polydispersity index (Mw/Mn) of extractable arabinoxylan, and yield and Calcofluor average molecular weight (Mcf) of extractable β-glucan

Extractability of β-glucan was higher in the bread made from milled rye kernels (35%)
than in the bread made from whole rye kernels (25%, Table 4), whereas β-glucan extractability was lower in both porridges (14%). The distribution
profile showed an elevated fraction of low molecular weight β-glucan in bread made
from milled rye kernels (Figure 1). Average molecular weight of extractable β-glucan in bread with whole kernels was
higher than in bread with milled rye kernels, indicating higher degradation of β-glucan
during bread-making. Extractable β-glucan molecular weight was similar between the
porridges.

The relative distribution of fructan molecules of varying degrees of polymerization
(DP) was very similar in the two porridges (Figure 2). The proportion of high DP fructan was higher in the breads, indicating the disappearance
of lower DP fructan.

Taken together, disintegration of the rye kernels had little impact on molecular weight
parameters of extractable arabinoxylan, β-glucan and fructan in porridges made from
whole kernels and milled rye kernels, while some differences could be seen between
the two rye breads.

Appetite ratings - Bread study

Before breakfast, the mean ratings for hunger, satiety and desire to eat were similar
between test days (Figure 3). Appetite ratings showed a clear effect of time after breakfast and after lunch,
i.e. the ratings visibly demonstrated the subjects' responses of lower hunger and
increased satiety directly after a meal and then progressively stronger hunger and
weaker feelings of satiety as the time approached the next meal.

Satiety was rated higher during the morning (08:30-12:00) after intake of both rye
bread breakfasts (Figure 3 and 4) compared with the wheat reference bread breakfast. The bread including whole rye
kernels also resulted in a reduced desire to eat compared with reference. Hunger ratings
did not differ significantly during the morning after intake of the three different
breads. During the afternoon (12:30-16:00), however, both rye bread breakfasts resulted
in increased satiety and reduced desire to eat compared with the wheat reference bread
breakfast. The bread with whole rye kernels also reduced hunger in the afternoon compared
with reference. Comparisons between the two rye breads (whole rye kernels vs. milled
rye kernels) revealed no significant difference in any appetite measure in either
morning or afternoon.

In summary, both of the rye breads resulted in increased satiety compared with the
wheat reference, but there was no difference in any of the appetite measures between
the two rye breads.

Appetite ratings - Porridge study

Baseline ratings for hunger, satiety and desire to eat were similar between test days
(Figure 5). During the morning (08:30-12:00), both rye porridge breakfasts resulted in increased
satiety, reduced hunger and reduced desire to eat compared with the wheat reference
bread breakfast (Figures 5 and 6). During the afternoon (12:30-16:00), the effect of breakfasts was still evident;
both rye porridge breakfasts resulted in increased satiety compared with the reference
breakfast with sifted wheat bread. The porridge made with rye kernels also reduced
hunger and desire to eat. Comparisons between appetite ratings after the two rye porridges
showed that the one made of whole kernels resulted in stronger satiety, lower hunger
and lower desire to eat during the afternoon than that made of milled rye kernels.

Discussion

The aim of this study was to investigate the effect of rye kernel structure on 8-h
subjective appetite. Whole and milled rye kernels were compared in a two-part study.
In the first part, the rye material was baked into breads and in the second part used
to make porridges. Sifted wheat bread breakfast was used as reference in both study
parts.

Both rye bread breakfasts increased postprandial satiety levels compared with the
wheat reference bread. This agrees with our previous findings, which showed a decrease
in hunger ratings during the 8-h period after consumption of rye bread breakfasts
including rye bran and sifted rye flour [12]. Similarly, bread that contained rye bran resulted in higher feelings of satiety
during 3 h after intake compared with reference wheat bread [21]. In contrast, no difference was reported in appetite ratings for a small group of
obese subjects with metabolic syndrome during 2 h after consumption of whole grain
rye bread compared with a combination of wheat and oat bread [22]. These breads were however not compared on an iso-caloric basis but the wheat and
oat bread contained slightly more energy.

The current study found no difference between the rye breads with different rye material
regarding effects on appetite. Contrasting to previous results showing that bread
with wheat kernels (over 80% kernels in total flour) increased satiety more than bread
with whole grain wheat flour during 2 h after intake [7].

Test products in appetite rating studies are often not well-characterized. In this
study, special efforts were taken to characterize dietary fibre content and structure
in the different test products. Processing had only small effects on the dietary fibre
content of breads made from whole or milled rye kernels. However, there was slightly
higher total dietary fibre content in bread made from milled rye kernels, probably
a result of higher resistant starch formation in the crumb during bread-making [23]. These minor differences in dietary fibre composition and molecular weight distribution
of extractable dietary fibre between the two rye breads did not result in any differences
in appetite, since both breads exerted similar appetite responses.

The fact that both of the rye porridges induced satiety more than the reference bread
confirmed results from previous studies [11,21]. Both porridges combine a number of potential satiety enhancing factors. Increased
food volume, by inclusion of water, was shown to increase satiety and decrease spontaneous
food intake in the short term [24]. In addition, the porridges provided much higher dietary fibre content than the reference
bread. Parts of the effect may relate to the viscosity-inducing properties of rye
dietary fibre.

In the present study, the weight and volume of the milled kernel porridge was three-fold
that of the kernel porridge, resulting in an immediate peak in satiety ratings. An
effect that soon disappeared and the two rye porridges had similar effects on satiety
during the morning hours. In the afternoon, milling of the rye ingredient seemed to
affect appetite, as the whole kernel porridge resulted in a stronger satiety, reduced
hunger and reduced desire to eat compared with the milled kernel porridge. Except
for the slightly higher resistant starch content in the milled kernel porridge, all
other dietary fibre components were similar. Thus, the effects can be solely related
to structure.

The mechanism by which the intact kernel porridge induced satiety in the afternoon
may be by reducing small intestinal digestion and absorption by forming a physical
barrier to digestive enzymes [25], hypothetically providing more material for colonic fermentation resulting in the
late increase in satiety. End products caused by colonic fermentation of dietary fibre,
such as butyrate, have been suggested to affect satiety. How this effect is mediated
is not clear. Suggested mechanisms are stimulated release of satiety hormones (GLP-1,
PYY) by L-cells in the colon [26]. An increased fermentation measured by breath hydrogen was recently correlated with
increased satiety [27,28]. A higher mean breath hydrogen excretion 4-6 h after consumption of rye kernels compared
with oat or wheat kernels indicating early and extensive colonic fermentation [27]. Rye bread intake has also been shown to lower the digestibility of protein, fat
and starch in a pig model [29], resulting in increased ileal excretion of macronutrients in ileostomi patients [30].

The present study showed significant differences in appetite ratings for up to 8 h
after intake of different breakfast meals. In order to do this, there was a need to
standardize energy intake during the whole period of measure. Therefore ad libitum
energy intake could not be included in the study design, at least not in the 8-h period
after breakfast, which would be most relevant. Appetite ratings have however previously
repeatedly been shown to correlate to and predict voluntary energy intake [31-33].

Future studies should explore whether the satiating effect of rye products is persistent
over time and if a diet rich in rye products could facilitate weight control.

Conclusion

This study demonstrates a satiety enhancing effect of whole grain rye foods, breads
as well as porridges, compared to an iso-caloric sifted wheat bread. Further, an interesting
effect regarding the influence of cereal grain structure was discovered. A breakfast
meal including whole rye kernels, resulted in increased feelings of satiety in the
afternoon, compared to porridge made of whole grain rye flour. The understanding of
the underlying mechanisms to the late response several hours after intake is likely
to involve colonic events and requires further investigation. Altogether, the findings
show that whole grain rye products improve satiety and lower hunger ratings. This
may explain how diets rich in whole grain and dietary fibre protect against overweight.

Competing interests

The study was supported by the supplier of the material used to make the test products,
Lantmännen. HI and HF are employed by Lantmännen R&D, the research and development
department of the Lantmännen Group. The authors declare that the data presented in
this publication represent a complete, true and faithful representation of the work
performed.

Authors' contributions

HI, RA, HF, JO and PÅ designed the study. HI recruited the subjects and performed
the study. AR carried out the dietary fibre characterization. RA and HI analyzed the
appetite data. HI and AR wrote the first draft of the manuscript. All authors participated
in revising the manuscript, read and approved the final manuscript.

Acknowledgements

For her assistance during the preparation of the test breakfasts we thank Sara Rundcrantz.
We would also like to thank nurses Nilla Fors and Eva Broman at KPL Good Food Practice
AB for performing the blood sampling at baseline. The study was financially supported
by a research grant from the Cerealia Foundation.

Le Gall M, Serena A, Jorgensen H, Theil PK, Knudsen KEB: The role of whole-wheat grain and wheat and rye ingredients on the digestion and fermentation
processes in the gut - a model experiment with pigs.